Culturing of cells for various diagnostic and research purposes is a standard technique. The cultivation of cell populations, such as lymphocytes, is used in tests of tissue compatibility, in the evaluation of the response of cells to certain types of drugs, antigens, allergens, etc. Cellular response is measured by the incorporation of radioactive tagging agents into the cell constituents. Cells are nowadays cultivated in standarized culture plates, generally having a plurality of 12 individual wells, of certain size and spacing. Such cell cultures are harvested by various devices, some of these quite sophisticated, but also rather complicated and expensive.